My father-in-law gifted me with an old (1929) edition of Mackey's Encyclopedia Freemasonry. This entry caught my eye.
Purity, Brothers Of. An association of Arabic philosophers, founded at Bosra, in Syria, in the tenth century. Many of their writings, which were much studied by the Jews of Spain in the twelfth century, were very mystical. Steinschneider (Jewish Literature, 174, 295) calls them the Freemasons of Bosra and says that they were “a celebrated Society of a kind of Freemasons.”